BP's response following a gas plant terror attack which left six Britons dead has been “inhumane to the extreme”, a widow of one of the victim's has claimed.

Systems supervisor Garry Barlow, 49, from Liverpool, died during the siege led by heavily-armed terrorists at the In Amenas gas plant, run as part of a joint venture including BP, in Algeria.

And his widow Lorraine said almost six months after the January attack she still has no idea how her husband was killed and has called for a full investigation to explore what happened.

Mrs Barlow also told BBC Radio 4's Today programme one of the most upsetting moments of the four-day siege was watching Prime Minister
David Cameron use a television address to warn the nation to prepare for bad news, as she had been given no prior warning.

BP said it remains an unresolved question how the terrorists breached an Algerian military zone and layered security measures and it will take part in the UK police investigation into the murders.

BP added Mr Barlow was employed by Swiss company IOTA and brought
in to work at the plant by the joint venture, which has its own management and operates independently.

When Mrs Barlow was questioned if BP had done enough to address her concerns in the aftermath of the incident, she said: "Not at all - quite the reverse. I've been shocked by BP. I expected a lot more of any
company with the name British in its title frankly.

"I just don't understand why they have actively chosen to distance themselves so far away from us that they feel they just don't need to communicate with us at all. They don't feel as if they have any responsibility to tell us anything. I find it quite shocking and inhumane to the extreme."

Mrs Barlow, mother to the couple's two teenage boys, said she had
several unanswered questions including what happened to her husband during the siege.

She said: "I don't know where his body was found, I don't know who found it, it's been such a long time now. Somebody must be able to tell us. I don't understand why we are not able to find out.

"We want a full investigation, we want to know exactly how this was allowed to happen. Garry was working in a supposedly safe and secure
location, in as much as he was in an oil field which was supposed to be
protected.

"Garry did not seem to receive any protection at all. Nobody came
to his aid. He waited, they all waited, in that office from when they heard the gunshots, they all waited for somebody to come to protect them
and he received no protection. And I'd like to know why."

Around 40 hostages were killed along with some 29 of the hostage-takers.

A BP spokeswoman said: "The terrorist attack at In Amenas was an unprecedented and horrific criminal terrorist act which has profoundly impacted the lives of many people. Our thoughts and sympathies remain with the families of all those who were killed.

"The In Amenas plant is run by a joint venture (JV) between Sonatrach (the national oil company of Algeria), BP and Statoil.

"The JV has its own management and operates independently.

"Some personnel are 'seconded' by the shareholders to the JV which also engages contractors and international agency personnel directly, including through Garry Barlow's Swiss employer IOTA.

"The In Amenas plant is situated within a military zone under the
control of the Algerian armed forces. How the terrorists were able to breach the military zone and the layered security measures to attack the
plant is an unresolved question.

"In the UK the police are conducting an investigation into the murders on behalf of the coroner.

"The evidence taken by the police in their investigation will necessarily be more comprehensive than evidence gathered by BP in an internal investigation. The police have powers to request and compel evidence and are able to work with law enforcement institutions in other
jurisdictions to collect evidence.

"BP will participate in this investigation and is co-operating fully.

"We shall only redeploy our expatriate employees in Algeria, and support the re-deployment of contractor personnel by the JV, as and when
we are satisfied with the safety and security conditions."